Milling machine



9 Sheets-Sheet 1 NAA? 1*.. s. WHITNEY MILLING MACHINE Filed Nov. 11 1924July 6', 1926. V

July 6,1926

9 Sheets-Sheet 2 9 Sheets-Sheet 5 July 6 1926. 1,591,595

L. s. WHITNEY MILLING MACHINE Filed Nov. 11, 1924 9 Sheets-Sheet 4INVENTO ORNEY M w Il .n EN..

`July 6, 1926.

L. S. WHITNEY MILLING MACHINE Filed Nov. 11,

9 Sheets-Sheet 5 July 6 1926.

L., S. WHiTNEY 1 MILLING MACHINE Filed Nov. 11, 1924 9 Sheets-Sheet 6NTO ORNEY July 6,1926.

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MILLING MACHINE 'Filed Nov. 11, 1924 9" Sheets-Sheet '7 July 6, 1926.

L. s. wHrNEY MILLING MACHINE Filed Nov. 11, 1924 9 sheets-sheet ATroRNEYJuly 6 1926.

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Filed Nov. '11, 1924 9 Sheets-Sheet 9 ATTORNEY Patented July 6, 1926. fY

LQLSQS LARNED'S. WHITNEY, OF FISKDALE, MASSACHUSETTS.

MILLING- MACHINE.

Appiication filed November 11, 1924. Serial No. 749,115.

The invention relates to milling machines, and more particularly tomilling machines adapted for cutting the spiral slot on auger bits.

The milling machine of the present invention has been developed inconnection with the new method of making auger bits constituting thesubject-matter of my cepending application Serial No. 749,114, filedNovember 11, 1924-. According to that method, as distinguished from themethods heretofore employed, all the various steps in making the augerbit are performed by precision machines, such as lathes and millingmachines. The spiral slot is described as cut by a milling' machine,preferably by the machine which is the subject-matter of the presentapplication. The more commonly practiced method of producing auger bitsat the present time is by drop forging, by which the tang, the shank,and the spiral rib which bounds the spiral slot are formed by dies. Theend of the bar of stoel from which the bit is hammered ont is firstheated and then subjected to the dies which form the bit. Drop forgedbits are often defective by reason of fire cracks and forging `defectsand vary considerably in length, diameter and general condition. Theoperations of converting the forged bit into the finished bit areexpensive. Moreover by reason of the variation in the sizes andvvgeneral condition of the drop forged bits it is often impracticable toemploy and other fixtures for the cutting of the lips, spurs and leadscrew, so that these operations must be perforn'ied by hand andtherefore at added cost.

The object of the present invention is to produce a milling machinehaving provision for cutting the spiral slot of an anger bit which iswholly produced' from a bar of round stock by machine operations. Prefeably the shank and tang are both formedl on the bit blank before thespiral slot is cut on the milling machine. By cutting the spiral slotrather than by drop forging it will be obvious that the spiral rib mayeasily be made concentric with the other parts of the bit such as thetang, shank, spurs and lead screw, and that therefore when the bit isplaced in the brace or bit stock it will turn true. Moreover byperforming all the operations of producing the bit on one imachine oranother from al bar of round stock (if slightly .larger diameter thanthe finished the spiral slot the stock fill be in milch bet-V tercondition for grinding and polishing than when the bit is drop forged.The foregoing and other advantages are secured in auger bit manufactureby means of the milling machine which is hereinafter more fullydescribed and is particularly pointed out in ythe appended claims.

ln the accompanying drawings illustrating the preferred form of theinvention, Fig. l.l is a side elevation of the improved milling machine;Fig. 2 is an end elevation, on an enlarged scale and partly in section,looking in the direction of the arrows 2-2 of Fig. 1; Fig. 3 is avertical section taken longitudinally through the spiral feed mechanism;Fig. 4i is a section taken on the line 4l-li of Fig. 3; Fig. 5 is asection on an enlarged scale taken along the line 55 of Fig. 1; Fig. 6is an elevation ofthe bit blank before the spiral slot has been out;Fig. 7 is a view of the bit blank after the spiral slot has been out;Fig. 8 is an end elevation of the gear casing, looking from the right inFig. 1, with the end cover removed; Fig. 9 is a view similar to Fig. 8looking from the left in Fig. 1; Fig. 10 is a section taken along theline 10-10 of F ig. 9; Fig. 11 is a section on a reduced scale takenalong the line 11-11 of Fig. 3; Fig. 12 is a section taken along theline 12 12 of Fig. 2; Fig. 13 is a section through one of the millingcutter heads; Fig. 11i is a detail illustrating the action of thecutters in cutting the spiral slot in the auger bit; Fig. l5 is adiagrammatic view (partlyin side elevation) to illustrate the positionsof the parts when a fresh bit blank has been placed in the chuck and themachine started in operation; Fig. 1G is a view similar to Fig. 15,showing the positions of the parts at the beginning of the spiral slotcutting operation; and Fig. 17

(Sheet li) is a section taken along the line 1.717 ofFig. 16.

VThe improved milling' machine as shown in. the illustrated embodimentcomprises a pair of oppositely disposed cutters 1 and 2, set at an anglewith each other, as shown diagrannnatically itl Fig; 1.4i The agf'ulmyet vico

difference between the positions of the cutters Will be determinedpartly by the pitch of the spiral slot and partly by the bevel or by theundercut of the Walls of the spiral rib ivhieh bounds the spiral slot.he cutters are disposed on opposite sides of the bit blank 3 and operatesimultaneously thereon, one of the cutters acting as a roughing cutterand forming one side of the spiral rib and the other cutter acting as afinishing cutter and forming the other side of the spiral rib. Theroughing cutter 1 which is of less Width than the finishing cutter 2 isset so as to out somewhat in ad y'ance of the latter. The bit blank 3 isheld by its tang 113 in a chuck d supported on the forward end of thefeed spindle 5. During the milling operation by which the cutters 1 and2 f rin the spiral slot in t-lie bit blank the body part 6' of the bitblank is supported in a guide or bushing S rising from the frame 9 ofthe machine which is supported by the legs 10.

1efore the bit blank is placed in the niilling machine the shank part 12has been turned doivn and the tang 13 formed thereon. The spiral slot iscut from the junction of the body part 5 and the s the cutting end ofthev bit. terminates short of the end The spiral slot of the bit to Uleave enough stock out of which to form the lips or cutting edges andthe spurs. Then the bit blank has been placed in the chuck the feedspindle 5 run for vard until the body part 6 of the bit blank is beyondthe cutters. rlhe cutters are then advancedtoward each other until theytouch the shank 12. Thereupon the feed spindle is moved in the reversedirect-ion (at the saine time being rotated) so that the cutters Willform in the body part of the bit a spiral slot of the requisite pitch.On the completion of the milling operation the cutters are disengagedfrom the Work, being moved outwardly from each other. and the bit blankentirely Withdrawn from the supporting guide 8. The n'iilling` cuttersare located opposite the middle of the guide S diagonally arranged slotsin the guide accommodate the cutters.

The cutter is mounted on the end of a spindle 15 journalen in a head 1Gadjustably secured by its flange 1T to the flange 1S of a housing 19which is movable toivard and from the bit blank synchronously with theho rsing 20 of the cutter 1 by means of the feed shaft 21 provided onits forward end with the handlel?. @n the front end of the shaft 21 is agear 24 Which meshes with a pinion mounted on the outer end of a shaft26 provided ivitlia Worin which passes through a block 28 secured to adovetailed slide 29, which slides toward and from the bit blank on thedove-tailed guide 80' in which the shaft 26- is journaled. In order thatthe housing` 19 may be adjusted hank 12 towardl tou/'ard and from thebit blank independently of the housing 20, it is provided ivith ay screw32 which past' s through the block 33 extending tiansve 1se'ly acrossthe slidc `turned the cutters are advanced toward and retracted from thebit blank independently of each other.

The head 1t? is provided with a 36 which is disposed at right to thelongitudinal axis of the head and which is received in the housing 19.Gn the forward end of the bearing is a Worm gear l? 1which vmeshes .vitha Worin 38 having 'its outer projecting end 39 squared to receive ahandle by which the angular position of the cutter 2 may be adjusted.rlhe housing 19 is provided With split blocks and when the cutter hasbeen adjusted.angularly the bolt 4l() is tightened to close the blocksou the bearing 86 and the bolts ll1' are tightened to secure the flanges17 and 1S together. 'lhe cutter 2 is driven by a pulley e3 mounted onthe outer end of a shaft 4st provided with a Worm Ll5 which meshes witha Worm gear 4:6 mounted on one end of the cutter sinn-dio 15. The partsfor supporting the cutter l in the housing 2O are constructed e like andhave the saine inode of operation as the parts connected With the cutterThe feed spindle 5, which carries on its forward end the chuck hismounted to have both an axial and a. rotative movement. 'For thispurpose it is journaled at its rear end in a pair of ball bearings 4f(and 48 mounted in the end Wall 49 of the gear casing 50, and at itsforward end in the ball. bearing 51 and a pair of ball bearings 52supported in a bushing 53 mounted in the end wall 5-1; of the casing 50.The axial movements for advancing the bit blank through and retractingit from the guide 8 are imparted to the feed spindle by a system ofgears enclosed in the gear Casing 50. This gear system comprises a wormgear 55 mounted by means of the pair of ball bearings 5G on the sleeve57 Which loosely eucloscs the ini-lille part of the feed spindle. TheWorm gear 55 is held against axial movement by the gear 58 and the checknut or split. collar 59. The gear 5S is mounted on the forward end of athreaded sleeve 60 and is secured to tho sleeve 57 by means of thethreaded portion 61 of the latter. The threaded sleeve reliieai'ingceives the threaded rear end of the feed, spindle and supports the ballbearings a7 and 48 which are held in the end wall l-9 between the gear58 and the cap 68.

The worm gear is driven by a worm 65 mounted on a shaft 66 journaled ina housing 67 mounted on the gear casing 50. On the outer end of theshaft 66 is loosely mounted a step pulley 68 which is adapted to drivethe shaft 66 through the clutch mechanism 69, when the dog 7lis'disengaged from the latch 7 2 of the clutch mechanism. This clutchmechanism is of well known construction and needs no detaileddescription. It is sutiicient to say that the pulley 68 is drivencontinuously, but that it does not drive the shaft 66 and the partsconnected with it so long as the dog 71 is in engagement with the latch72. Wlhen the dog 7l is disengaged from the latch 72 the pulley 68 isoperatively connected with the shaft 66 through the clutch mechanism.The latch 72 then rotates with the shaft until the dog is againinterposed in its path of travel.

When the feed spindle is moved in a left hand direction (viewing Fig. l)to advance the bit blank through the guide 8 into position for thecommencement of the slot cutting operation, the feed spindle is causedto move several times faster than when it travels in a right handdirection (viewing Fig. l) to effect the cutting of the spiral slot.This mode of operation is secured by changing the operative connectionsbetween the worm gear 55 and the feed spindle according as the latter iste be moved in the one direction or the other. During the slot cuttingoperation the driving connection between the worm gear 55 and the feedspindle is 'made as followsz-Journaled in the body of the worm gear 55are three shafts 74, each carrying at its right hand end (viewing Fig.8), a gear 75. Each gear 75 meshes with a gear 76 mounted on a studA78secured in the worm gear 55. The gears 76 all mesh with and drive gear58 and thereby impart an axial movement to the feed spindle through thethreaded sleeve 60. As the worm gear 55 rotates in a clockwisedirection, viewing Fig. 4;, the revolution of the gears 75 and 76 aboutthe feed spindle causes the gears 76 to rotate on their axes and therebyturn the gear 58 and the threaded sleeve by which the feed spindle iscaused t-o travel axially in a right hand direction, viewing Fig. 3.

When the feed spindle is to be moved to the left to advance the bitblank through the guide into position for'the slotI cutting operation,the driving connection between the worm gear 55 and the spindle is madeas foilowsz-0n the sleeve 57 is mounted a flanged collar 84t'carrying amovable drum or clutch member 85 having on one edge of its perimeter atoothed ring 87 and on the other edge of its perimeter a toothed ring88. The teeth of the ring 87 are adapted to engage with the teeth of thering 89 secured vto the worm gear 55, and the teeth of the ring 88 areadapted to engage with the teeth of the ring 90 secured to the internalwall 82 of the gear casingl 50. When 'the feed spindle is moved to theright Vthe ring 87 is in engagement with the ring 89 and under theseconditions the drum, 85 turns with the worm gear 55. When on the otherhand the feed spindle is to be moved to the left the ring 88 is inlocking engagement with the ring 90, as shown in Fig. 8, and the drum 85is prevented from turning. Under these conditions the rotation of theworm gear 55 causes the three pinions 92 formed on the left hand ends ofthe shafts 74; to travel over the internal gear 93 cut in the perimeterof the drum 85. This causes the gears 75 to rotate relatively rapidlyand thereby impart a relatively rapid rotation to the gear 58 and thethreaded sleeve 60. The pinions 92, the gears 7 5, and the gear`58 areso related in size that the travel of the feed spindle in the left handdirection is about three times its rate of travel in the right handdirection. It will be obvious that by changing the sizes of the gearsthe difference between the rate of travel of the feed spindle in the twodirections may be increased or decreased.

In order that a spiral slot may be cut in the bit blank a rotativemovement is imparted to the feed spindle while it is traveling axially.For this purpose a gear 95 mounted on the outer end of the threadedsleeve 69 drives the gear 96 (Fig. 8) through -the idler gear 97. rThegear 96 is mounted on one end of a shaft 98 journaled in the cnd wall i9and the end wall 54.- of the gear casing. On the other end of the shaft98 is a pinion gear 100 which meshes with an idler gear 101 mounted on ashaft 102 (Fig. 10) jeurnalcd in the wall 54. On the forward end of theshaft 102 is a second idler gear 108 -which meshes with and drives agear 1044 tixedly mounted on the bushing 105 on which the pair of ballbearings 52 are mounted. The bushing 105 has a spline and slotconnection with the forward end of the feed spindle so as to permit thcaxial movenientof the spindle throughthe bushing while the latter turnsthe spindle. By vary-V ing the sizes of the gears 95 and 96 the pitch ofthe spiral slot to be cut in the 'bit blank may be varied as desired. i

When abit blank has been placed in the milling machine with its tang inthe chuck 4 the machine is started in operation by turning the handle107 in a counter-clockwise direction to disengage the dog 7l from thelatch 72. rlie handle 107 is iiXed on 'the front end of a transverseshaft 108, on the rear end et which (Fig. 5\ is tired an arm i nn sin;

109 connected. by means ot the link 111 with the arm 112 tixed on thepivot pin 113 on which the dog 71 is mounted. The li-nk 11 is providedwith a tarn buckle 114 to vary the operative position ot the dog 71. Themachine continues in operation so long as the lowei` end o1z thedownwardly projecting arm 115 ot the handle 107 is held engaged by thenotch 116 ot the latch or arm 117 (Figs. 15, 16 and 17) pivoted at 11S.'lhe-arm 117 is held in engagement with the arm 115 by means oi' aspring pressed pin-nger 120 mounted to slide vertically in a boss 1.21.When the arm 117 is disengaged from the arm` 115 (in the manner to beefplained presently) the spring 122 interposed between the boss 12S andthe outer end et an arm 12d fixed on the shaft 108, acts to turir theshaft 106 and the handle 1,07 in a clockwise direction thereby placing`the degni-.1. in the path ol' rotation ot the latch i2 to stop themachine.

Since the forward movement of the bit blank'through the guide S issimply tor the purpose ot putting the bit blank in position tor'the slotcutting` operation by the cntters 1 and 2, the drum 85 is moved intolocking engagement vith the stationary ring when the machine is startedin operation so as to cause the spindle to move torward at its greaterspeed. The drum 85 is moved into locking engagement with the stationaryring 90 by litting the handle 126 mounted on the front end of atransverse shaft 127 (Fig. 5), the rear end of which carries an arm 126.rllhe tree end ot the arm 128 is connected by the link 129 with theouter end ot an arm 130 secured to the pin 131 which passes through ayoke havingl two downwardly extending arms 132 (Fig. which straddle thecollar Si and are provided at their lower ends with inwardly projectingpins 133 adapted to be loosely engaged by the flanges 1311 of thecollfll l..

Tdlhen the handle 126 is lilted to throw the drum into lockingengagement with the stationary ring the square boss 136 on the rearside'ot the handle is caught and held bv a latch or notched arm 137piveted at 136 on the mac iine frame. The bit blank continues to advancethrough the gindeso long` as the handle 126 is held in its raisedposition by the arm 1237. The arm 1537 is yieldingly held in itsoperative position by means ot a spring 189 interposed between the boss1410 (Vl-tig. 5) on the ma.- chine 'trame and a washer 1.43 held on thelower end et a rod 14:4 pivotally connected with the free end ot' thearm 137. The arm 167 in the path ot oscillation ot an arm 1x16, looselymounted on the stud 147. llVhen the lower end of the swinging arm 146strikes the arm 137 (as will be presently eX- plained) to disengage it,trom the handle` 126, the spring 148 surrounding the lower end ot thelink and interposed between the bracket 1110 and the tree end ot' thearm 126, acts to move the link 129l downwardly and thereby disengagethev drum 85 from the stationary ring 90 and shift the drum intoengagement with the worm gear 55. Thereupon the feed spindle moves inthe reverse direction and the bit blank is withdrawn relatively slowlythrough the guide 6 during which time the spiral slot is cut.

llhenl the bit blank has advanced through the guide. 8 into posit-ionfor the beginning oit the milling operation, the handle 126 isdisengaged trom the notched arm 137 by the *following means r--Mountedon the stud 1&7 is a slotted disc 150. rrdjustably secured in thesegmental slot 151 ot the disc is a dog adapted when the disc rotates ina clockwise direction to contact with a pin 153'projecting rearwardlyfrom the lower end of the swinging arm 146 and move the arm into contactwith the tree end ot the notched arm 167 to disengage the latter fromthe square boss 1516 oit the handle 126. lllhile the Jfeed spindle istraveling in a left hand direct-'ion to at vance the bit blank throughthe guide 6 the disc rotates in a clockwise direction, indicated in Fig.15. 0n the rear side of disc ismounted a gear 155 which meshes will andis driven by a pinion 156' mounted n the forward end ot a shatt- 157journaled in the liront part ot the gear casing 50i On the rear end otthe shaft 157 is mounted a worm gear 156 which meshes with and is drivenby a worm 159 mounted on the shaft 102. The position ot the dog 152 onvthe disc 150 is determined bythe length of theV body part ot the bit,and the body part varies in length the dog` 152 is adjusted accordingly`so that the handle 126 will be released and the drum 85 shi'tted intoengagen'lent with the worm gear when the bit blank is in position 'forthe beginning ot the'millingr operation. l

l At the saine time the handle 126 is released and the drum 85 movedinto engagenientwith the worm gear 55 to cause the bit blank to bewithdrawn through the guide 8 tor the milling operation, the milling'cutters are autonnitically brought into position to cut the slot. Forthis purpose the shatt 21 is provided with a downwardly extending arm160 the 'free end ot which is connected by means of the adjustable link161 with the tree end of the arm 162 of a bell? crank pivoted at 166' ona bracket 164 secured to the end ot the machine trame. The other arm 165ot the bell crank carries a weight 166 which serves to pull the link 161to the right (viewing Fig. 1), thereby turning the shat't 21 in acounter-clockwise direction to advance the millingy cutters toward eachother into position to cut the spiral slot.

Qn the completion of the slot ca ittingenerA ation the operative turnsthe handle 22 in a clockwise direction -from the position shown in Fig.16 to the position shown in Figs. 1 and 15, thereby withdrawing thecutters from the Work and moving the link 161 to litt the. Weight 166.llhe Weight is held in its raised position by the engagement ot the arm168 fixed on the shaft 163 With a latch or notched arm 169 pivoted at170 on the bracket 164. The lower free end of the notched arm 169 ispivotally connected by means ot' the adjustable link 171 With 'the 'treeend of the arm 146. The arm 169 is yieldingly pressed into lockingengagement With the arm 168 by means of a spring 172, one end or' whichtakes against the tree end of the arm 1.69 and the other end against theWasher 17 8 lixed on the outer end of a pin 1711 pivotally mounted at175 on the bracket 1611. lhen the rotation of the disc 150 brings thedog 152 into engagement With the pin 153 on the rear side of the 'arm1416, the link 171 is moved to the left disengaging the notched arm 169from the arm 168 thereby permitting the Weight 166 to drop, turning theshaft 21 and advancing the cutters toward the Work. In order that theremay be no shock as the Weight 166 descends, a dash pot 177 is provided,the piston rod 178 olf Which is connected by a link 179 with an arm 180mounted on the shait 163. The depth o1 the spiral slot cut by themilling cutters is determined by the engagement of an arm 182 secured tothe rear end of the shaft 21 with an adjustable stop 188 mounted on abracket 184C secured to the machine frame.

lt Will conduce to clarity ot description and a more ready understandingot the mode ol: operation of the machine in cutting the spiral slot toassume at this stage that the bit blank has been placed in the chuck,that the handle 107 has been turned to start-the machinein operation andthat the handle 126 has been lifted to cause the bit blank to advancethrough the guide 8. When the bit blank has advanced through the guide 8into position l'or the slot cutting operation the dog` 152 engages thepin 158 on the arm 146 and moves the arm 1116 against the latch arm 137to disengage it from the handle 126 so as to permit the drum 85 to bemoved into engagement with the worm gear to cause the feed spindle totravel in the reverse direction to Withdraw the bit blank through theguide. This reversal of the axial movement of the feed spindle isaccompanied by a reversal o1 its rotative movement so that the disc 150now travels in a counter-clockwise direction. At the same time the arm146 is disengaging the arm 187 from the handle 126 it disengages thelatch arm 169 from the arm 168 thereby permitting the descent of theWeight 166 to turn the shaft 21 to advance the cutters 1 and 2 towardeach other and into position for the slot cutting operation. Thepositions ofV the parts in the beginning of the slot cutting operationis shown in Fig. 16.

During the spiral slot cutting operation the feed spindle 5 travels inthe direction or the arrow (Fig. 16) and has a rotative. movement in. acounter-clockwise direction so as to liorm a right hand spiral rib onthe bit. lVhen the spiral slot has been cutV (enough stock being' leftat the end o1" the bit to iorm the lips and spurs) the dog 186adjustably secured in the segmental slot 187 in the disc 150, engageswith the end oi the arm 188 and acts to disengage the latch arm 117 fromthe handle 107 as shown in Fig. 1 The arm 188 is pivot-ed at 118 and isyieldingly held against the pin 185 on the latch arm 117 by means of thespring 189. The release ot the handle 107 from the latch arm 117 permitsthe spring 122 to move the 'dog 71 into the path of the latch 72 tobring about the stopping of the machine.

lVhen the machine has stopped the operative. turns the handle 22 fromthe position shown in Fig. 16 to the position shown in Figs. 1 and 15.The turning of the handle 22 disengages the critters -from the Work andfrom the guide 8 and at the same time liits the Weight 166 which is heldin its raised position by the engagement of the arm 168 with the latch-arm 169, the travel of the dog 152 in the counter-clockwise directionduring the slot cutting operation permitting the spring 172to torce thearm 169 into position to catch the arm 168 when it is lowered While thearm 165 and the Weight 166 are raised. The positions ot the parts atthis point in the slot cutting oper` ation is shown in Fig. 1.

lllhen the cutters have been disengaged from the Work and from the guide8 the perative turns the handle 107 to the left to start the machine inoperation again to effect the Withdrawal ot the bit blank from theguide. Since at the beginning of this operation the dog 186 is incontact with the arm 188 it is necessary for the operative to hold thehandle 107 until the dog 186 has moved clear ot the arm 188, at Whichtime the spring pressed plunger 120 forces the latch arm 117 up intoholding engagement with the lower end ot the handle 107. The machinethen continues to operate until the dog 191 contacts with the end of thearm 188 thereby again disengaging the latch arm 117 from the lower endoli the handle 107 and stopping the machine. This occurs when the bitblank has been completely withdrawn irom the guide, as shown in Fig. 157the position ot the guide being indicated by the cutters 1 and 2.

The mode of operation of the improved milling machine may now be brieflyrecapitulate'd as followsz-Atter the bit blank lili has been Withdrawnfrom the guide 8v on the completion or" the slot cuttingope-ration, thedog 191 'remains in contact with the end ot the arm 188, as shown inFig. 15. r1`hus it will` be understood that when a 'tresh bit blank isplaced in the chuck and the machine is started in operation, (the disc15() now turning in a clockwise direction when the handle 126 is liftedto throw the drum 85 into engagement with the stationary ring 90 to`cause the bit blank to travel toward the guide 8), the operative. willhold the handle 10T until the dop; 191 has cleared the end ot the arm188. fis the disc continues to rotate in clockwise direction While thebit is advancing through the guide, the dog 186 moves into Contact withthe end ol thearin 188, but inasmuch as 'this arm is yieldinglyconnected With the latch arm 11, the dog` 186 simply lifts the arm 188as it passes by it, the spring 189 return* ing the arm 188'to normalpositionon the 1 Y. i e

latch arm 111.

TheA disc-150 continues to rotate in a` clockwise direction (while thebit blank is advancing, through the guide 8 into position forthebeginningr of the slot cutting` operation), untilV the dog' 159Jstrikesv the pin 158 on the rear side oi 'the arm 146. As the disc 150continues to `rotate with. the dog' 152 in engagement with the pin 158,the link 1T1-is moved to Vthe le'tt disengagingl the latch arm 169 fromthe arm 168, 'thereby permitting` Athewveigjht 166 to descend and dra-wthe link 161 to theright.. rEhis movementcauses the sha-'tt 21 to beturned in a counterclockivise direction and 'the cutters to be' advancedtoward each other and into position for cutting the slot. When vtheshatt- 21 is turned the handle 2Q is raised 'trom the position shown inFins. 1 'and 15 to the positionshown in Fig. 16. t about the same timethat the latch arm 169 'is disengaged 'from the arm 168 to cause 'thecutters to be advanced into cutting position, the arm 146 disengagesthe.latch arm 137 frointhe handle 126, thereby permitting the spring 148to disengage the drum 85 troni the ring 90 and move it into engagement-With the Worm gear to cause the ieed spindle totravel in the right handdirection to uf'ithdraiv the bit blank through the guido for the slotcutting operation.

The shitting of the drum .from -en gagement with the ring` to enf.)gement withthe Wornigear 55 causes the disc 150 to rotate in acounter-clockwise direction as indicated in Fig. 16. Bise 150 continuesto rotate in this direction yuntil the dog;l 186 strikes the end of thearm 188 and disengages the latch 117 'from the handle 167, therebystopping' the machine. This occurswhenthe spiral slot reaches almost the*cutting` endot the bit, leavingl only enough stock for the lips andspurs. The operative nowy turns the handle from the position shown inFig. 16 to the position shown in Figs. 1 and 15, thereby disengag'ingthe cutters from the slot and from the guide, and lifting the Weight 166which is held in its raised position by the engagement o't the arm 168with the latch arm 169. When this has been done the operative againstarts the machine in operation by turning` the handle 10T, holding' thehandle until the dog 186 has passed beyond the end of the arm 188. The'feed spindle now continues to move toward the right to entirelywithdrav.' the bit 'lrom the g'iiide 8. T'ffhen the teed spindle hasmoved tar enough to the right to permit the bit to be removed from thechuck and a 'fresh blank to be placed therein, the machine is stopped bythe dos,` 191 coming` incontact `with the arm 188'as shown in Fig. 15.

Having;` thus described the invention what I claim as new is 1. Amachine for milling the spiral slot of a bit blank provided witha bodyportion, a shank and a tana', comprising, a spindl\n mountedto moveaxially and rotatively and carrying,` a chuck to hold the bit by itstang,

a pair ot cutters arranged to operate on opposite sides ot the bit andmounted to move toward and from each other, means 'for imparting' a.simultaneous axial and rotative moven'ientto the spindle so as toe'liect the cutting' of the spiral slot, ,means 'lor advancine,` the bitto bring' the shank opposite the cutters, a Weight connected with thecutters and arranged when released to `move the cutters toward eachother to slot cutting position, and means operative when the shankportion o'l the'bit is opposite the cutters to release the Weight and tocanse the spindle to be moved in the direction to ei'ect the cutting;`ot the spiral slot.

2. A machine 'lior'cutting` the spiral slot of an auger biteon'iprising, a cuter, a spindle carrying a chuck for holding' the bit`m aus Jfor supporting-the spindle so that it may have an axial and arotative movenient, said spindle being;` provided with a threadedportion, a threaded sleeve mounted on the threaded part of the spindle,a gear tired on the sleeve, a bushing; having a sliding,Y connectionwith the si'iindleand arranffed to turn therewith, a near fixed on thebus una', means 'for turning` the two gea rs to impart a sin'iultaneousaxial and rotative movement to tliewspindle, means tor reversiup; thedirection o'f the axial: and rotative movements ot` the spindle,\a discdriven by the means 'foractuating` the spindle, said disc'turi'iing inthe one direction Whenthe spindle advances toward the cutter and `in theother direction When the spindle is retracteditrom the Cutten'mea-ns'lier-setting the machine in motion to bring the bit into position forthe beginning` of the slot cutting,`

operation, and means controlled by the disc for advancing the cutter toslot cutting position and for causing the spindle to travel in thedirection to effect the cutting ot the spiral slot.

3. A machine for cutting the spiral slot of an auger' bit comprising, acutter, a spindle carrying a chuck to hold the bit, said spindle havinga threaded portion, a threaded sleeve mounted on the threaded part ot'the spindle, a gear lined on the sleeve, a bushing having a slidingconnection with the spindle and arranged to turn therewith, a gear fixedon the bushing, means :tor turning the gears to impart a simultaneousaxial and rotative movement to the spindle, means for reversing thedirection ot the axial and rotative movements of the spindle, a weightarranged when released to move the cutter into slot cuttingposition,means connected with the means for actuating the spindle to release theWeight when the bit is in position for the slot cutting operation andmeans `for stopping the machine on the completion ol the cutting of theslot.

1l. A machine tor milling the spiral. slot ot an auger bit comprising, aspindle mounted to move axially and rotatively and carrying a chuck forholding the bit, means for imparting a. simultaneous axial and ro-ytative movement to the spindle, means for reversing the axial androtative movements oiI the spindle, a cutter mounted to move toward andfrom the bit, a Weight connected with the cutter and arranged whenreleased to move the cutter toward the bit into slot cutting position,means for holding the weight in raised. position, and means operativewhen the bit-has been moved into position for the beginning of the slotcutting operation to release the Weight.

5. A machine tor milling the spiral slot ot an auger bitcomprising, aspindle mounted to move axially and rotatively and carrying a chuck forholding the bit, means 'for imparting a simultaneous axial and ro`tative movement to the spindle, means 'for reversing the axial androtative movements o'll the spindle, a cutter mounted to move toward and:from the bit, a Weight connected with the utter and arranged Whenreleased to move the cutter' into slot cutting position, means i'orholding the cutter in raised position, a disc connected with and drivenby the means for actuating the spindle, a handle for start-,ing themachine in operation, a second handle lor controlling the direction olimovement of the spindle, means on the disc for releasing the weight andfor controlling the operative position of the second handle, and othermeans on the disc for con trolling the operative position of the iirsthandle.

6. A machine for milling the spiral slot of an auger' bit comprising, aspindle mounted to move axially and rotatively and carrying a chuck forholding the bit, a pair of oppositely disposed, angularly arrangedcutters mounted to move toward and from the bit, means for imparting asimultaneous axial and rotative movement to the spindle to advance thebit between the cutters into position for the beginning of the slotcutting operation, means for reversing the direction of movement of thespindle, a weight connected with the cutters and arranged, whenreleased, to move them toward each other into slot cutting position,means lor holding the Weight in raised position, a disc connected withand driven by the means for actuating the spindle, a handle torcontrolling the direction or' movement'of the spine dle, and means onthe disc for releasing the Weight when the bit is in position Vlfor thebeginning of the slot cutting operation, said means on the disc actingsimultaneously to change-the position oi the handle for the slot cuttingoperation.

7. A machine for milling the spiral slot of an auger bit comprising, aspindle mounted to move axially and rotatively and carrying a chuck forholding the hit, a pair or oppositely disposed, angularly arrangedcutters mounted to move toward and from each other, means for impartinga simultaneous axial and rotative movement to the spindle so that thespiral slot may be cut in the bit, means for moving the bit intoposition for the beginning of the slot cutting operation, a rotatingdisc driven by the means for actuating the spindle, a handleV forcontrolling the direction of movement of the spindle, means for holdingthe handle raised while the bit is moving into position for thebeginning of the slot cutting, a dog on the disc for releasing thehandle to reverse the movement of the spindle, and a Weight connectedWith the cutters and arranged when released to move the cutters towardeach other, said dog acting, when releasing the handle, to release theWeight.

8. A machine tor cuttingspiral slots comprising, a spindle mounted tomove aaiallyY and rotatively and carrying a chuck ior holding the Workin which the spiral slot is to be cut, a cutter, said spindle having athreaded portion, a threaded sleeve mounted on the threaded part otl thespindle, means for turning the sleeve to impart an axial movement to thespindle, a bushing mounted to slide on the spindle and to turntherewith, means for turning the bushing to rotate the spindle, meansfor reversing the axial and rotative movements of the spindle,

a disc connected with and driven by the means for actuating the spindle,said disc. turning in one direction When the Work is advanced toward thecutter and turning in the opposite direction when the Work is Withdrawnfrom the cutter, a handle for starting CIK c means on thedisc lo engagewith the second handle to reverse the movements el the spindle, andmeans 'for advancing the cutter toward the worl'; when the movements otthe spindle are reversed.

9. A machine for cutting spiral slots comprislng, a. spindle mounted. tomove axially and rota-.tively and carrying a chuck Jfor holding the workin which the spiral slot is to be cut, a cutter, means Yfor iiiipartingan axial movement to the spindle in two directions, means for impartinga rotative movement to the spindle in two directions, means :torreversing the axial and rotative movements ot the spindle, a discconnected with and driven by the means for actuating the spindle, ahandle for starting the machine in operation, a second handle torccntrolling the direction orp movement et the spindle, and meansconnected with the dise for controlling the operative positions ot thehandles according to the position ot tac Work with respect to thecutter.

10. A machine for cutting sp'ral slots comprising, a spindle mounted tomove axially and rotatively and carrying a chucl to hold the work, acutter, .means .tor imparting a siniult-aneous axial and rotativemovement to the spindle, means 'lor reversii'ig the axial and rotativemovements of the spindle, a disc driven by the means tor actuating thespindle, a handle 'for starting the machine in operation, a secondhandle for controlling` the direction ot' movement or" the spindle, adog on the disc for actuating the second handle to reverse the directionof movement of the spindle, and means for advancing the cutter' towardthe word for cutting the slot, said dog acting to operate the last namedmeans when the work is in position t'or the slot cutting operation.

11. A machine ior milling the spiral slot of auger bits comprising, aspindle carry ing a chuck for holding the bit, said spindle having athreaded portion, a threaded sleeve mounted on the threaded part ot thespindle, a gear iiXed on the sleeve, a worm gear loosely mounted on thespindle, means tor driving the worm gear in one direction only, adriving gear 'ulcrumed in the web of the worm gear, an idler gearbetween the driving-gear and the gear on the sleeve, a drum mounted toslide on the spindle, a gear on the drum, means Lor locking the drumagainst turning, means tor shitting the drum into engagement with theworm gear to turn therewith, a pinion connected with the driving gearand adapted to mesh with the gear on the drum, a bushing mounted toslide on and turn with the spindle, a gear on the bushing, connectionsbetween the gear on the bushing and the sleeve by which rotativemovements are imparted to the spindle, a cutter, means for starting themachine in operation to advance the bit past the cutter, and means formoving the cutter toward the bit to cut the slot.

12. A machine for milling the spiral slot of an auger bit provided witha body portion, a shank and a tang, comprising, a spindle carrying achuck to hold the bit by the tang, a pair of oppositely disposed cuttersmounted to move toward and from each other, said spindle being providedwith threaded portion, a threaded sleeve mounted on the threaded part elthe spindle, a gear iiXed on the sleeve, a worm gear loosely mounted onthe spindle, means for turning the worm gear in one direction only, adriving gear tulcrumed in the web ot the worm gear, an idler gearbetween the driving gear and the gear on the sleeve` a bushing mountedto slide on the spindle and to turn therewith, a gear ixed on thebushing, driving connections between the sleeve and the bushing, a drumhaving an internal gear, means for locking the drum to the worm gear toturn therewith, means for shifting the drum, means for holding the drumagainst turning, a pinion on the driving gear adapted to travel over theinternal gearon the drum when the latter is held against turning, a discdriven by the means for actuating the spindle, a handle the position ofwhich determines the direct-ion of movement of the spindle, a weightconnected with the cutters and arranged when it descends to move thecutters toward yeach other into slot cutting position, means Yforholding the weight in raised position and means connected with the discttor acting on the handle to change the direction el movement ot thespindle and to release the weight to move the cutters into slotcuttingposition.

LARNED S. VHITNEY.

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